


The Impossible

by MizJoely



Series: Dust to Dust (Infinity War/Endgame series) [2]
Category: Sherlock (TV)
Genre: Avengers: Endgame (Movie) Spoilers, Crossover, F/M, Sherlolly - Freeform, loads of feels
Language: English
Status: Completed
Published: 2019-05-03
Updated: 2019-05-03
Packaged: 2020-02-16 15:49:15
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,398
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18694552
Author URL: https://archiveofourown.org/users/MizJoely/pseuds/MizJoely
Summary: "Once you have eliminated the impossible, whatever remains - however improbable - must be the truth." A follow-up to my Avengers: Infinity War fic "The Unthinkable". Warning for Endgame spoilers.





	The Impossible

**Author's Note:**

  * For [mychakk](https://archiveofourown.org/users/mychakk/gifts).



John stumbles and catches himself on the edge of the chair. What the hell just happened? One minute he was handing Rosie to Sherlock and the next he's alone in the sitting room of 221B Baker Street.

No, not alone; he hears Rosie's soft snores coming from the portacrib settled between the end of the sofa and the messy desk. So whatever it was that just blacked his memory - if Sherlock's drugged him he swears he'll kick his arse from here to Sherrinford and back again - at least Rosie's fine.

He starts to move toward the crib, intent on making sure, absolutely sure, that she's fine (where is Sherlock, why did he leave them alone?) when a sound catches his attention. He turns toward the kitchen, and is startled to see Molly Hooper standing there, a sturdy cast-iron frying pan clutched tightly in her hands. "Hey Molly, when did you get here? Where's Sherlock?"

She opens and closes her mouth a few times, but seems unable to speak. He moves toward her, brow crinkled in worry, but a sound from the crib catches his attention; Rosie is fretting and he knows better than to assume she'll cry herself back to sleep. "Don't worry, Daddy's coming," he calls out and hurries over to pick her up.

That is, he starts to hurry over; a loud cry from Molly causes him to stop, to turn to face her again. She's charging toward him, the frying pan held high like a weapon. "Stay away from him!" she screams, and he stumbles back as she swings at him.

"Molly, what the hell-?!" John exclaims.

She swings at him again, missing by a good few inches, then jabs the pan at him, a wild, terrified look in her eyes. "I don't know who you are or what you're playing at, but this, this is  _sick_ , how  _could_ you - you get  _out_ of here, Sherlock is on his way home, he'll be here in minutes you twisted  _bastard-_!"

John stares at her, bewildered, stunned by the unreasonableness of her reaction. Maybe he isn't the one who's been drugged, maybe she has? But Sherlock would never do that to her, Molly would kick him to the curb in no uncertain terms were he to try something so idiotic on her.

But he can't come up with any other explanation as she continues to stare wildly at him, keeping herself between him and the crib. "Molly, I just-" he tries, but she's having none of it.

"Get out of this flat," she hisses. "Get out now, before Sherlock gets here and breaks your neck for pulling such a heartless-do you really think you'll be able to fool him? You'd better start running and never stop if you want to live, you bastard!"

She's shaking, but he has no doubt that she'll use that frying pan on him should he try to get nearer to her. But Rosie's starting to cry in earnest now, and he has to try to figure out how to get his daughter away from the apparent madwoman standing in front of him.

The sound of feet pounding up the stairs distracts Molly; he makes a feint to her right and manages to shove her over, shouldering her so that she falls to the floor with a scream. He'll apologize to her later, once he figures out what the  _hell_ is going on but right now Rosie needs him.

"Hush Rosie, it's all right, Daddy's here," he says, but the words dry up in his throat as he stares down at the child sitting in the crib, staring up at him through (brown, not blue) eyes swimming with tears. The hair is a tangled mess of (dark brown, not blonde) curls, and the clothing...this isn't his daughter, it's a little boy of the right age and size but definitely not his Rosie.

The pounding footsteps have morphed into a shout. "Molly! Molly, you'll never believe-!"

He turns to face Sherlock, who skids to a stop as he enters the flat, his eyes shining with a strange, unsettling combination of hope and fear. In his arms is a little girl (blonde hair, blue eyes) possibly six or seven years old, her arms tight around his neck. She stares at him blankly (why does that hurt, he's never seen this little girl before) but squirms to be let down when she sees Molly struggling back up.

"Let me down Uncle Lock, Aunt Molly's hurt!" she demands.

Sherlock lets her down without once removing his gaze from John's puzzled, wary face. "It's true," he whispers, taking a step forward. "My god it's true."

He smiles, an open, dazzling smile like none John has ever seen on his lips before. His eyes - is Sherlock Holmes actually  _tearing up_?

"Sherlock?" Molly's voice catches his attention; he tears his gaze away from John's with what seems to be a great deal of reluctance, then hurries over to help her to her feet. He then reaches into the crib and lifts the fretting toddler into his arms, and John's eyes widen as he sees the definite resemblance - somehow, impossibly, this little boy looks like a perfect blend of Sherlock and Molly.

"How-?" he starts to ask, beyond bewildered, but is stopped as Sherlock rushes forward and engulfs him in an enormous bear hug, still holding - his? - child.

He's talking, speaking rapidly, but the words make no sense to John. "It's true, Molly, it's true! I wouldn't have believed it but...Nasir's son just reappeared in front of him, at Speedy's, looking exactly the same as he did the day he vanished! And look outside - the trees, the people, Molly! They're back, they're all back!" He lets John go just enough to haul Molly into his embrace. "Even Mrs. Hudson," he whispers, tears still falling from his eyes. "She's making tea, Molly - tea! She has no idea - John," he interrupts himself, once again meeting his gaze. "John, what do you remember? Anything?"

"Uncle Lock." The small voice is firm. "You're not making sense. Why does this man look like my Daddy?"

"Because I am your Daddy." "Because he is your Daddy."

Both men speak at the same time, Sherlock joyfully, John with a growing, stunning sense of shock. Whatever remains, however improbable...this little girl is his Rosie, five years older than when he last saw her, just a few minutes ago. And the toddler is Sherlock and Molly's son and what the  _hell_ happened to cause this time shift?

"That's impossible," Molly whispers, but the suspicion and fear are gone, replaced by uncertainty. "Sherlock, it's impossible - isn't it?"

He shakes his head, still smiling so brilliantly it almost hurts. "They're back, Molly. They're all back."

He lets her and John go, gets down on one knee, still holding his son who has stuck a thumb in his mouth and is watching everything through solemn brown eyes. "Rosie, you know about the Vanished, and how your Daddy and your other godmother, Mrs. Hudson, were among them?" She nods. "Well, something happened and they've all been brought back. So yes, this is your Daddy, John Watson."

He gazes up, eyes positively shining. "He's back, they're all back."

Molly stifles a sob, gesturing for Sherlock to hand her their son. "Come on Johnny," she says as she cuddles him close. "Let's...let's get some...oh God, Sherlock, Mrs. Hudson! She doesn't know, we have to tell her…"

"She's making tea, she'll bring it up, we'll explain it to her and John at the same time," Sherlock assures her. He kisses her tenderly, puts an equally tender kiss on his son's forehead. _Johnny, they named him after me?_ John thinks, feeling like he might just pass out if he doesn't sit down. Right. Now.

So he does, more or less collapsing onto the straight-backed chair behind him. He's staring at Rosie, can't take his eyes off her, and she's looking back at him with the same forthright, assessing gaze Mary used to have when she was puzzling something out.

"Hi Daddy, I'm glad you're not vanished any more," Rosie says, moving closer and leaning her head on his shoulder.

"So am I, Rosie, so am I," he whispers, leaning his head on top of hers as he waits for Mrs. Hudson and the answer to the myriad questions scrambling madly through his mind.


End file.
